The viability theory face to reality-testing: From Julia to Gaia

Patrick Saint-Pierre
– Université Paris-Dauphine, France

In 1985 Jean-Pierre Aubin and Georges Haddad had laid the mathematical foundations for viability theory. Theorems developed since then has explored the mathematical power and depth of this approach. The development of numerical tools helped to give it essential color and visibility. But was it enough? By browsing the path from theoretical applications to the study of concrete problems we will see how it has been possible to give relevant answers to a problem whose complexity precisely reflects a reality that is delicate to apprehend through the lens of an agro-ecological problem presented in the paper: "Agroecological transition: A viability model to assess soil restoration", co-authored by Marie-Hélène Durand, Anna Désilles, Patrick Saint-Pierre, Valérie Angeon, and Harry Ozier-Lafontaine and published in the Natural Resource Modeling journal in 2017. This paper has been awarded with the "Lamberson Medal" in 2018.

Research theme

GERAD

GERAD is a multi university research center founded in 1979, financed by FRQNT.
It involves some seventy experts from a mix of disciplines: quantitative methods for management, operations researchers, computer scientists, mathematicians and mathematical engineers, from HEC Montréal, Polytechnique Montréal, McGill University and Université du Québec à Montréal.